The frames, B,
and the wheels, G, are secured upon the hollow shafts, so that they can
not move independent of each other. Shafts are placed within the hollow
shafts, H, upon which the communicating wheels, D, and the center
wheels are secured, so that they can move independent of the frames, B,
and wheels, G.

While the
frames, B, make one revolution, the wheels, D, and the center
wheels make two revolutions. This is caused by the action of the
weighted levers E. Their weight, or inertia, prevents them from passing
around the center of the axis of the wheels with which they are
suspended in the revolving frames. The full force of this resistance,
or inertia, is applied to the other wheels of each set, and by these
wheels communicated to the center wheel.

Nature bears long with those who wrong her. She is patient under abuse. But when abuse has gone too far, when the time of reckoning finally comes, she is equally slow to be appeased and to turn away her wrath. (1882)
-- Nathaniel Egleston, who was writing then about deforestation, but speaks equally well about the danger of climate change today.

Carl Sagan:
In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.
(1987) ...(more by
Sagan)

Albert Einstein:
I used to wonder how it comes about that the electron is negative.
Negative-positivethese are perfectly symmetric in physics. There is no
reason whatever to prefer one to the other. Then why is the electron
negative? I thought about this for a long time and at last all I could
think was It won the fight! ...(more by
Einstein)

Richard Feynman:
It is the facts that matter, not the proofs. Physics can progress
without the proofs, but we can't go on without the facts ... if the
facts are right, then the proofs are a matter of playing around with
the algebra correctly. ...(more by
Feynman)